Amalgatale (One Shot)
by OmegaArts13
Summary: PatrolTale spin-off. Story about what happened in Amalgatale, AU where Gaster came up with devilish plan to take revenge to the humankind...


**Amalgatale**

 **Author Note : Enjoy. So far creepiest AU I have come up with, that might make return in PatrolTale somepoint as visited AU... Feel free to suggest me Aus for Patrol!Sans and Patrol!Frisk to visit in part 3 of the story, once we get there.**

 **As usual, all caps text (LIKE THIS) is spelled in Windings.**

Sans would be running through the Judgement Hall, looking behind, but not daring to stop. As he ran towards the throne room and the barrier, he tried to recall how these events started, only few hours ago...

"SANS!" Papyrus called, as Sans snapped awake, having fallen asleep middle of breakfast. "...Yes Bro?" Sans asks, to which Papyrus just frowns. "Did you stay up late in laboratory again?" Papyrus asks. Sans looks a bit to the ground. "...Yeah, worked myself to the bone", Sans says, winking, which Papyrus just stares at him. "...Puns, really?" He asks, looking disappointed. Sans smirks. "...Well, Tibia to be honest, it has been real busy back in the lab." Papyrus shakes his head. "...Well anyhow, weren't you supposed to be there five minutes ago?" Sans blinks, looking at clock. "...Oh sugar honey ice tea!" He says, as he shortcuts to the lab, leaving confused Papyrus to the kitchen. "...Sugar honey ice tea?" He asks, tilting his head a bit.

At the lab, Sans would change his usual jacket into a lab coat, making his way through the halls. Gaster and Alphys would be waiting, turning their heads as Sans arrives. "AH, SANS. YOU'RE LATE", Gaster greets, coughing a bit. Alphys looks at Gaster, worried. "...You should not push yourself, we are working as fast as possible..." Sans looks at Gaster, then Alphys. "...How is his condition?" Sans asks. Alphys shakes her head. "...He should be resting, but it is impossible to stop him..." she explains. Gaster looks at readings. "...TOO MANY MONSTERS HAVE FALLEN DOWN", Gaster says, coughing. "...WE NEED TO FIND CURE AS SOON AS POSSIBLE, BEFORE IT BECOMES AN EPIDEMIC", he then says. He then looks at a Soul in a container. "...I BELIEVE THAT BY STRENGHTENING OUR SOULS WITH HUMANS MIGHT BE ENOUGH, BUT... WE ONLY HAVE ONE..." He thinks, looking at it. "BUT IF WE COULD EXTRACT DT FROM IT..." He thinks, taking the soul to the DT Extractor. "WE MIGHT BE ABLE TO COME UP WITH A CURE", he then says, starting DT Extractor, Souls colour fading from blue to white as Determination is extracted from it, Gaster holding the vial up. "...THERE. THIS SHOULD BE THE CURE..." He says. "NOW, WE JUST NEED TESTSUB-" he begins, as a white petal-like bullet is shot at the vial.

In a next moment, without a warning, Vial shatters, all the DT falling over Gaster, before his body absorbs it. Alphys and Sans look horrified, as Gaster blinks, looking his hands. "...WHO DID THAT!?" Gaster asks, calling angrily, looking around but is not able to see anyone. Alphys meanwhile would check the readings, blinking. "...D-doctor, your soul... The c-cracks are closing!" Alphys calls out. Gaster blinks, looking at his soul. "...IT IS CURE..." He says. "WE NEED TO GET MORE SOULS HOWEVER" he then adds, looking at the white human soul. "...Well, if the situation is here under control, you mind if I go to look who did this?" Sans asks. Gaster nods. "DO SO", he replies. Alphys meanwhile stays monitoring progress, as Sans begins to look around for one who broke the vial.

Once outside, Sans is thinking. "...I can think one weed who might had done that", he thinks, using his shortcut to warp to the Waterfall. Once there, he would meet a flower, arguing with a echo flower. "Hey, weed", Sans calls out, earning Floweys attention. "...What you want smiley trash bag?" Flowey asks. Sans sighs. "How long have you been here?" He asks. Flowey thinks. "...Not sure, but for a while... Been arguing with this smug bastard..." He says, "Smug bastard" Echo flower replies, causing Flowey lash at it. "Told you to shut up!" "Shut up!" Echo flower replies, making flowey frown angrily before destroying it with his petal bullets. Sans narrows his eyes. "...Just wondering, someone tried attack doc with a bullet, very similar to yours", Sans informs. Flowey looks at Sans. "Well, wasn't me. He never leaves that lab, and I cannot go there even if I'd want", Flowey says. "I hate hotlands", he then adds. Sans frowns. "Well, that makes sense-" He says as his phone calls. Sans picks the phone up. "Hotlands Hot Cats, how can we be a service?" Sans asks. "R-really Sans? Alphys asks, sighing. "...N-no matter... W-we got a p-problem! D-docs readings went h-haywire... I-i don't know what hapen- ...D-doctor? W-what are you do- STAY AW-" Alphys manages to say before line goes dead. Color seems to escape Sans' face, as he shortcuts to the lab.

Once back at the lab, place would look like a hurricane went from there, all the vials and containers shattered, DT extractor broken and no-one in sight. "...What in name of Asgore happened here..." Sans thinks, as he shortcuts to the where security records are saved. "...Should had done this from the start", Sans thinks, as he goes back to point where vial was shattered. While attacker is not visible, one thing is certain... Shape was not a flowers, but something that resembled a spider, that then ran away through the vents. Sans frowns, going forward the tapes, then stops to point where Alphys called to him, slamming both his hands to the desk as he sees what is happening. Gaster would had began turn entirely white, then started to drip, before making his way to Alphys. There, his semi-liquid body surrounded the dinosaur monster – in process, Gasters size grew a bit. Same repeated with other scientists, who tried to stop Gaster, without success. Sans swears. "...What happened..." He says, before realizing that Gaster had left the laboratory. Sans looks around, realizing that Gaster had broken the alarm systems, disabling them entirely. His expression froze, as he watched through the cameras and realized that Gaster was heading towards Waterfall, and there to the Snowdin.

Next few hours were darkest the underground ever had seen. Denizens of the Hotlands were first to be consumed by Gaster. Undyne and the Royal Guard, along with denizens of the Waterfall were easily overtaken. Despite their attempts to escape, people of Snowdin also fell victims of Gaster and were consumed, along with Papyrus, despite Sans' efforts to tell his brother to escape. Former queen was next victim, along with those who lived in the ruins. And now, IT was heading towards the capital.

Arriving to the end of Judgement Hall and to the Throne Room, Sans finds that Gaster had already made his way there and added Asgore to the his list of the victims. He looked at Sans. "sAnS" it began to speak in glitched voice. "jOiN uS", it then says, face becoming more distorted as it launched several gooey tendrils at Sans, who shortcutted to other end of the throne room. Gaster looks at him. "iT iS nO uSe", Gaster says. "yOu CaNnOt EsCaPe... No OnE cAn!" It says, as Sans once more dodged the amalgamate. As he looked around, Sans noticed a mechanical spider, that then proceeded to fire petal-like projectiles at him. "...You did this", Sans says, looking at machine. Gaster also looks at it, as it digs itself to the ground, a image of Gaster appearing to it, who smiles. "SANS. IF YOU ARE HEARING THIS, THAT MEANS MY PLAN TO END HUMAN-KIND HAS BEEN SUCCESS, AND I HAVE BECOME THE ULTIMATE WEAPON", Gaster says. Sans' eyes widen. "...You set this up yourself", Sans says, to which Gaster smirks. "AS MY WORDS ARE BY NOW PROBABLY GLITCHED, LET ME INTRODUCE MYSELF, WITH MY NEW NAME... AMALGASTER", Gaster says as Amalgaster destroys the recording, lunging once more at the Skeleton, who dodges. He then feels something crawling on his arm.

Sans notices Flowey, who wraps himself around Sans' arm.. "...Weed, are you planning to get us both eaten?" Sans asks. Flowey glares at Sans. "Hell no! We need to get away from it!" He then says. "And I don't want to be eaten, so I stick with you for the time being!" Flowey says. Sans frowns. "...We can't let it reach outside world either", Sans thinks, summoning his Gaster Blaster. Amalgaster laughs. "yOu ThInK tHaT wIlL wOrK oN mE?" he asks. Sans smirks. "Oh, I am not aiming for you", he says, as he blasts the roof of the entrance to the barrier, collapsing it and shutting only exit of the Underground. "nOoOoOoO!" Amalgaster roars, as he tries to stop exit from collapsing. Sans and Flowey use the moment to escape, as Amalgaster glares around the place. "tHeRe Is No EsCaPe!" He then roars.

In snowdin, Sans frowns. "...Welp we are boned", Sans says, shaking his head. "...We have no escape, and we are stuck in underground with him", he says. Flowey frowns. "...Were the puns necessary?" He asks. Flowey then notices a strange light from Papyrus' room. "...Hey, what is that?" Flowey asks. Sans looks at the light, then narrows his eyes. "...One way to find out", he says. Entering room, Sans finds a gate of some kind. "...Any idea what is that?" Flowey asks, as something breaks the front door. "...Nope, but I don't think you want to stay here and deal with him?" Sans asks. Flowey looks at Amalgaster. "yOu WiLl NoT eScApE!" Amalgaster roars. "Jumpinjumpinjumpin!" Flowey screams, as Sans smirks and jumps.

Once in other side of the barrier, Sans would shoot Gaster Blaster at the gateway, collapsing it, leaving Amalgaster to the other side. Sans and Flowey both sigh. "...Now, where are we..." Sans asks, looking around, realizing he is in outside world in somewhere. "...Where..." He asks, looking down the hill, seeing a village. "...Well, one way to find out", he thinks, pulling his coats hood to hide his face, and making his way to the village...

 **Afterword : I hope you enjoyed Amalgatale! We might see Sans and Flowey again though, In PatrolTale... Stay tuned!**


End file.
